How to train and predict using bag of words?

Question

I have a folder of images of a car from every angle. I want to use the bag of words approach to train the system in recognizing the car. Once the training is done, I want that i

Answer 1

Your next step is to extract the actual bag of word descriptors. You can do this using the compute function from the BOWImgDescriptorExtractor. Something like

 bowDE.compute(img, keypoints, bow_descriptor);

Using this function you create descriptors which you then gather into a matrix which serves as the input for the classifier functions. Maybe this tutorial can guide you a little bit.

Another thing I would like to mention is, that for classification you usually need at least 2 classes. So you also need some images which do not contain cars to train a classifier.